Yes an ERROR() geometry even better. I suppose that is not part of the OGC specs.
I was thinking that if it did at least return an empty collection - then I could inspect the ones that returned an empty collection for issues or simply throw them out with a filter if I didn't want to be bothered with them, but an ERROR() geometry would be better to differentiate from truly empty collections. Thanks, Regina -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Paul Ramsey Sent: Wednesday, March 12, 2008 1:18 PM To: PostGIS Users Discussion Subject: Re: [postgis-users] Topological Exceptions Hard. An "ERROR()" geometry type is almost called for, so that you can run the whole set and actual inspect post-facto which ones failed. The most annoying part of the current behavior for me is the difficulty tracking down the problematic pair of geometries. I think you're right, the current fail-and-stop behavior causes more problems than it solves. On 3/11/08, Obe, Regina <[EMAIL PROTECTED]> wrote: > > > I've been doing a lot of work using ST_Intersection, ST_Difference, ST_Union > etc to cut out slices of geometries I don't want and slicing up geometries > into smaller pieces, reunioning etc. > > I've been running into a lot of Topological Exceptions of the form directed > Edge this and non-noded that. For the most part I've been able to overcome > these by slicing things smaller or skipping over problem regions (e.g. areas > where the difference is a line or point or something of that sort). > > I think a lot of people have run into the same issues and have gotten > frustrated and there doesn't seem to be a simple solution suggested to > overcome these. > > Is there any way we can change (add overloaded functions or some setting > parameter) - that take additional parameters to simply ignore these errors > that says return empty collection or NULL when a GEOS error is thrown. That > way I can simply ignore these and throw them out of my equation and move on. > > Just a thought. I'm sure my suggestion is rather simple-minded and I'm sure > I'm missing some reason of why this is not feasible. An explanation of why > my suggestion is stupid at anyrate would be nice. > > Thanks, > Regina > > > ________________________________ > > > > > The substance of this message, including any attachments, may be > confidential, legally privileged and/or exempt from disclosure pursuant to > Massachusetts law. It is intended solely for the addressee. If you received > this in error, please contact the sender and delete the material from any > computer. > > ________________________________ > > > > > Help make the earth a greener place. If at all possible resist printing > this email and join us in saving paper. > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users ----------------------------------------- The substance of this message, including any attachments, may be confidential, legally privileged and/or exempt from disclosure pursuant to Massachusetts law. It is intended solely for the addressee. If you received this in error, please contact the sender and delete the material from any computer. _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
